Cutter



July 3, 1934. l

R. w MCLEAKN 1,964,786

CUTTER .50 between the parts Patented July 3, 1934 UNITED STATES PATENT'OFFICE CUTTER Application June 4, 1932, Serial No. 615,373

2 Claims.

This invention relates to cutters, knives, or like devices used inpower-driven machines running `at high speeds and in which the knives orcutters are subjected to hard and abusive treatment ne- 55 cessitating.their frequent replacement. While the improved knife or cutter formingthe immediate subject of the present invention is of broad utility, Ihave herein chosen to illustrate and describe it as embodied in acottonseed huller as represen- 10 tative of machines of this generalclass and wherein its peculiar characteristics are highly advantageous.

A cottonseed huller usually consists of a rotary drum or cylindercarrying knives spaced circum- 15 ferentially about its periphery andadapted to cooperate with similar knives mounted in one or more concavemembers arranged adjacent to the drum, such as is shown in my priorPatent No. 1,590,305, granted June 29, 1926, the seeds to be a0 crushedor hulled being fed between the drum or cylinder and the stationaryconcave member and being subjected to the crushing or cutting action ofthe two sets of knives.

In machines of this character, the cutting ele- 25 ments are subjectedto heavy shocks and severe usage, and frequently small hard objects findtheir way into the machine and often destroy the cutting elements beforesuch objects can be removed. Due to the heavy loads and severe shocks,30 the cutting elements usually are made of comparatively heavy stock(for example, lig of an inch thick). In order to facilitate replacementand permit the individual cutting elements to be reversible andinterchangeably secured in the .35 holder, each cutter commonly isprovided with a longitudinally extending groove or recess in each face,midway between its cutting edges, this groove receiving suitablefastener elements such as bolts having annular shoulders which hold thebar 40 against radial or outward movement.

Such constructions are not wholly satisfactory in that the long groovesmaterially reduce the strength of the knife or cutter, so that thecutters sometimes bend or break at this weak cross section. Moreover, asthe cutters are held in place merely by the engagement of the shoulderof the bolt with the groove, there is usually only a line contactbetween these elements, and in many cases only a point contact. The unitpressure may thus become very great, while furthermore, the cutters areheld against outward or radial movement only, no provision being madepositively to prevent movement ofthe cutter in the longitudinaldirection relative to the holder, If the fastening member becomesloosened, worn, or crushed by the severe shocks which it sustains, alongitudinal shift in the position of the cutter is permitted, while thelooseness of the cutter not only interferes with the accuracy ofoperation of the machine, but also results in the ou premature dullingof the cutter and the necessity of frequent renewal or replacement, allof which adds substantially to the operating expense of machines of thischaracter.

The principal object of this invention is to provide an improved cutterwhich is of simple design, which is of rugged durable constructionadapted better to withstand the severe usage encountered in suchoperations and to remain tightly fixed in its original position in itsholder, which is inexpensive to manufacture, and which overcomes theaforementioned objectionable vfeatures inherent in the cutters of priorconstructions while still retaining their reversible, interchangeableand readily removable character.

Further objects and advantages will be apparent from a consideration ofthe following description and the accompanying drawing which exemplinesone embodiment chosen for the purpose of illustration.

In the drawing, l

Fig. 1 is a vertical cross-sectional View of a cottonseed huller showingthe cylinder and portions of the concave in end elevation;

Fig. 2 is an elevation of one form of my improved cutter;

Fig. 3 isa sectional detail of a portion of the huller cylinder showingthe improved cutter and one fastening member in assembled relation withthe holder;

Fig. 4 is an enlarged sectional detail showing the complementalinterengaging elements of the cutter and fastening member; and

Fig. 5 is a section on the line 5 5 of Fig. 4.

Referring to Fig. l, the machine comprises a rotary cylinder or drum 1mounted upon a shaft 2 and provided with a series of circumferentiallyspaced cutter elements or blades 3. Cooperating with the cylinder 1 is aconcave, here shown as made up of two parts 4 and 5, each part beingpivotally mounted adjacent to the base of the machine, the part 4 beingpivoted at 6 and the part 5 at 7. These parts may swing away from thedrum 1 by breaking one or more frangible links (not shown) in the eventthatany hard substance, such as a stone or piece of metal, should getbetween the teeth of the cutting edges, so as to avoid too great damage.The peripheral surface of the drum or cylinder l and the inner surfacesof the concaves are furnished with substantially radial iigblade-receiving slots of the usual character and dimensions, which areadapted to hold the usual thick and rigid, forged or cast blades orcutters of substantially rectangular cross section. One side wall of theblade-receiving slot constitutes an abutment element against which thecutter is rmly held, as hereinafter more fully described. Suchconstructions are well known and are fully set forth in my prior PatentNo. 1,590,305, to which reference may be had for a more completedescription.

In accordance with the present invention the cutters or blades 3 aremade from a relatively thick piece of metal, having in general asubstantially rectangular transverse section of such dimensions as to tsnugly in the blade-receiving slots, the longitudinal edges of the bladedefining its cutting edges. On opposite faces, and midway between itscutting edges, the blade is provided with two or more symmetricaldepression or dimples 10, preferably spaced at equal distances from theends of the blade. Preferably these depressions extend longitudinally ofthe blade and are of toroidal contour. The ends of the blade may beprovided with suitable notches 12 which permit the insertion of a toolfor removing blades which may have become pressed into firm engagementwith the holder due to the clamping action of the retaining member. Eachof the blades is similarly constructed so that it may be reversed in theholder and interchanged with other blades in both the concave andcylinder.

Adjoining the blade-receiving slots are the usual recesses 14 whichreceive the heads 15 of retaining members or bolts 16. Each bolt headpreferably is provided with an annular shoulder 18 having a contourconforming to that of the depressions 10. Preferably the outer edges ofthe shoulders are of toroidal shape and adapted snugly to t within thedepressions 10 to dene therewith complemental interengaging surfaces forholding the blade rmly in place in the retaining slot. When the blade 3is to be assembled in the machine, it is rst inserted part way into theblade-receiving slot and the bolt 16 is threaded part way into place sothat its annular shoulder 18 and depression 10 are brought into looseengagement with each other, it being understood that a plurality ofthese bolts are similarly arranged along each of the slots. The boltsmay then be tightened, bringing the blades downwardly into rm engagementwith the bottom of the retaining slot, as shown in Fig. 3.

Referring to Figs. 4 and 5, it will be noted that the shoulder 18 anddepression 10, being symmetrical and conforming in contour, define asurface contact of substantial extent which positively locks the bladeagainst transverse and longitudinal movement relative to the holder. Itwill be further noted that the depressions constitute but a very smallpercentage of the crosssectional area of the blade and consequently donot weaken the blade to any appreciable extent.

While I have shown and described one desirable embodiment of thisinvention, it is to be understood that the present disclosure is for thepurpose of illustration only and that various changes in shape,proportion, and arrangement of parts, as well as the substitution ofequivalent elements for those herein shown and described, may be madewithout departing from the spirit and scope of the invention as setforth in the appended claims.

I claim:

1. In a machine of the class described, the combination of a holderhaving an elongate blade-receiving slot, an elongate blade fittingwithin said slot, said blade having a plurality of dimples in each ofits opposite faces, all of said dimples being substantially midwaybetween the cutting edges of the blade, and a bolt for holding saidblade and holder in assembled relation, said bolt having acircumferentially extending shoulder with a contour conforming to thatof said dimples, said shoulder and dimples dening complementalinterengaging parts which lock said blade against transverse andlongitudinal movement relative to said holder, the blade having notchesat its opposite ends for the insertion of a tool for use in removing theblade from its slot.

2. A cutter for use in a machine of the l class described, said cuttercomprising an elongate metallic blade of substantially uniform andrectangular cross section, whose longitudinally extending edges arecutting edges, the opposite faces of said blade each having a pair ofelongate dimples therein, extending longitudinally of the blade andarranged substantially midway between its cutting edges, the ends of theblade having notches therein for the reception of a tool for removingthe blade from operative position in the machine. 4

ROBERT W. McLEAN.

